1. Field of the Invention
The present invention relates to high-travel elevator systems that are installed in, e.g., high-rise buildings.
2. Description of the Related Art
The travel of an elevator system is generally not more than 700 to 800 meters as restricted by the weight of the ropes for suspending a car. Thus, passengers must utilize a plurality of vertically arranged elevator systems to climb higher than the aforementioned travel by making connections from one elevator system to another.
FIG. 14 is a diagram showing the construction of a conventional double-deck elevator system disclosed in, e.g., Japanese Patent Application Laid-open No. 9-165149. A first hoisting machine 12 moves a first double-deck frame 11 up and down along a lower hoistway 13. A second hoisting machine 15 moves a second double-deck frame 14 up and down along an intermediate hoistway 16. Finally, a third hoisting machine 18 moves a third double-deck frame 17 up and down along an upper hoistway 19.
The lower end of the intermediate hoistway 16 neighbors the upper end of the lower hoistway 13. The lower end of the upper hoistway 19 neighbors the upper end of the intermediate hoistway 16. A first car 21 is mounted on upper portions of the double-deck frames 11, 14 and 17, and moves up and down within the hoistways 13, 16 and 19. Further, a second car 22 is mounted on lower portions of the double-deck frames 11, 14 and 17, and moves up and down within the hoistways 13, 16 and 19.
Further, the first and second cars 21 and 22 are pushed by pushing devices 23a to 23h at a communicating space between the lower hoistway 13 and the intermediate hoistway 16 and a communicating space between the intermediate hoistway 16 and the upper hoistway 19, so that the cars 21 and 22 move between the first and second double-deck frames 11 and 14 and between the second and third double-deck frames 14 and 17. That is, the first and second cars 21 and 22 move up and down along the three hoistways 13, 16 and 19 by transferring from the double-deck frame 11 to the frame 14, and then to the frame 17, and by transferring in the reverse thereof.
In the conventional elevator system constructed as described above, space to accommodate two neighboring hoistways must be ensured at each relay floor, decreasing building utilization efficiency. Further, the three hoistways 13, 16 and 19 are not arranged linearly, and this complicates the architectural design of the building. Still further, in order to move the cars 21 and 22 between the double-deck frames 11 and 14, and 14 and 17, the double-deck frames 11 and 14 or the double-deck frames 14 and 17 must be stopped side by side at the relay floor and then the cars 21 and 22 must be pushed. This slows the movement of the cars 21 and 22 between the double-deck frames 11 and 14, and 14 and 17, thus impairing passenger handling efficiency.